Arrangement for cutting threads on double stitch sewing machines

ABSTRACT

Thread cutting device for double stitch sewing machines having a looper turning in a horizontal plane, a bobbin housing secured against turning movements by means of a retaining finger resting against an abutment in the stitch plate, an outlet opening for the looper thread determining the course of the looper thread between stitch plate and bobbin housing and a thread catcher having a point cooperating with a cutter and movable in a horizontal plane where the outlet for the looper thread is disposed below the plane of the surface of the bobbin housing at its wall facing the needle, preferably in the area of the retaining finger, and the point of the thread catcher is movable below the plane of the surface of the bobbin housing between the path of movement of the needle and the retaining finger of the bobbin housing.

United States Patent ns1 3,658,021 Hedegaard et al. [451 Apr. 25, 1972[541 ARRANGEMENT FOR CUTTING 2,866,425 'i2/195s Paimbacn ..112/-184 XTHREADS 0N DOUBLE STITCH 2,163,994 6/1939 Fischer ..112/ 252 3,21 1,117lO/l965I Speichermann et all. ..112/252 [72] Inventors: KristenHedegaard, Gentofte, Denmark; Anton Lessmeister, Hutschenhausen, Germany [73] Assignee; Firma (l. M. Pfaff/11., Kaiserslautern am ll'nlz.(iermnny [22] Filed: Aug. l0, 1970 [21] Appl. No.: 62,574

[30] Foreign Application Priority Data Aug. 16, 1969 Germany ..1 19 41681.0

[52] U.S.Cl ..112/252 [5 l] Int. Cl. t D05b 65/02 [58] Field of Search..1 12/252 [56] References Cited UNITED STATES PATENTS 3,503,355 3/1970Hagemeyer et al. ..112/252 Primary Examiner-James R. BolerAttorney-Robert H. Jacob [5 47] ABSTRACT Thread cutting device fordouble stitch sewing machines having a looper turning in a horizontalplane.. a bobbinhousing secured against turning movements by means of aretaining fingerresting against an abutment in the stitch plate, anoutlet opening for the looper thread determining; the course of thelooper thread between stitch plate and bobbin housing and a threadcatcher having a point cooperating with a cutter and movable inahorizontal plane where the outlet for the looper thread is disposedbelow the plane of the surface of the bobbin housing at its wall facingthe needle, preferably in the area of the retaining finger, and thepoint of the thread catcher is movable below the plane of the surface ofthe bobbin housing between the path of movement of the needle and theretaining fingerof the bobbin housing.

S Claims, 10 Drawing Figures PATENTEUAPR 2 5 is?? SHEET 3 UF 3BACKGROUND OF THE INVENTION The invention relates to thread cuttingdevices for sewing machines. More in particular, the invention concernsa thread cutting arrangement for double stitch sewing machines having alooper or catcher that rotates in a horizontal plane, a bobbin housingmounted in the looper against rotary movements secured by means of aretaining finger that rests against an abutment on the stitch plate,with an outlet for the looper thread that determines the course of thelooper thread between the stitch plate and the bobbin housing, and athread catcher movable in a horizontal plane that cooperates with acutter, with a catcher point and a recess formed thereon for receivingthe needle and the looper thread.

ln a known thread cutting device a thread catcher that is movable abovethe bobbin housing surface is provided which is pivotally movable aboutan axis that is disposed generally parallel to the looper shaft. Thepoint of the thread catcher is offset rectangularly and provided with aV-shaped incision where the two legs of the thread catcher defined bythe incision are moved in an essentially vertical plane between thebobbin housing and the retaining finger that extends laterally andupwardly from its housing surface and seize the needle thread, as wellas the looper thread during the first part of the thread catchermovement. The two threads seized are disposed during the further courseof the thread catcher movement in front of an aperture that extends fromthe intersection ofthe two legs ofthe Vshaped incision and are guidedand severed by a cutter entering this aperture. The arrangement of thetwo legs is such that the upper leg of the thread catcher moves abovethe plane of the bobbin housing surface and the lower leg below theplane ofthe bobbin housing surface. ln this manner, it is insured thatduring the thread catching movement of the thread catcher, the threadthat leaves the aperture at the top side of the bobbin housing and leadsfrom there to the stitch hole, as well as also the part of the needlethread loop that rests during the guiding of the needle thread aroundthe bobbin housing on its upper side is seized. The part of the needlethread loop that is moved during the guiding of the needle thread aboutthe bobbin housing over its upper side is with loopers of this type ofconstruction always the thread supply leading to the needle thread loopso that this thread catcher seizes and cuts the looper thread and thepart of the needle thread loop that leads to the thread supply. The partof the needle thread loop leading to the sewing material extends duringthe thread catching movement of the thread catcher along the lowerpartof the bobbin housing and thence below the bobbin housing stop fingerbetween the surface of the bobbin housing and the inside of the looperbody to the stitch hole and cannot be seized by the thread catcher thatmoves along a path of movement extending between the retaining fingerand the housing surface of the bobbin housing. With the olderarrangement the threads are severed almost centrally at their seizinglocation by the cutter that dips into the aperture of the thread catcherso that the part of the needle thread loop leading to the material is atleast as long as the part that extends to the thread supply. Since theend of the needle thread that remains with thethread supply must be of alength that insures the forming of the starting stitches ofthe nextfollowing sewing cycle, there results an undesired length for the needlethread end remaining on the sewing material due to the almost centralseparation of the needle thread loop which for certain sewing operationsrequires a shortening of the needle thread end that must be effectedmanually. Beyond that, the thread catcher that moves above the uppersurface of the bobbin housing makes it necessary to place the looperlower which is not advantageous due to the displacement ofthe thrustofthe needle movement for reasons ofsewing technique.

SUMMARY OF THE INVENTION It is therefore an object of the invention toprovide a thread cutting means for double step stitch sewing machineshaving a looper that rotates in a horizontal plane which makes itpossible to seize the part of the needle thread loop leading to thematerial and the looper thread by means of only one thread catcher thatdoes not influence the level or height of the looper.

ln order to accomplish this, the invention is based on the technicalproblem to so constitute the course of the looper thread from the bobbinhousing to the stitch hole, while insuring flawless stitch formation,that the looper thread together with the part of the needle thread loopleading to the sewing material can be seized with a thread catcher thatmoves laterally of the bobbin housing.

This problem is solved in accordance with the invention in that theaperture for the looper thread is arranged below the plane of thesurface of the bobbin housing at the part of its casing surface facingthe needle, preferably in the area of the retaining finger, and thepoint of the thread catcher is movable below the plane of the surface ofthe bobbin housing between the path of movement of the needle and theretaining finger of the bobbin housing.

With double stitch loopers of the type referred to above, the looperthread is guided from the bobbin disposed in the bobbin housing througha slot that is usually directed obliquely upwardly in the housingsurface of the upper part of the looper housing below its tensioningspring through to an outlet opening provided on the surface of thebobbin housing in the area of the abutment lug for the bobbin housingvent and from there extends obliquely upwardly to the stitch hole.

With the former looper construction, the looper thread extends from itsoutlet opening practically in the same plane as the part of the needlethread loop that moves during guidance of the needle thread around thebobbin housing over its surface to the thread supply. With thearrangement of the aperture for the looper thread in accordance with theinvention, the looper thread leads from its aperture provided at itspart of its housing surface facing the needle below the plane of thebobbin housing surface between the housing surface of the bobbin housingand the inner wall of the looper body through to the stitch hole, thus,it extends to tlhe stitch hole below the plane of the bobbin housingsurface and thus also below the part of the needle thread loop that isto be moved by the looper below the plane of the bobbin housing surfaceto the thread supply. If in this connection the looper thread outletopening is arranged in the region of the retaining finger of the looperhousing closely above its bearing rib, then the looper thread emergingfrom its opening extends during the period of greatest loop expansion ofthe needle thread nearly parallel to its part leading to the sewingmaterial and is seizable in its region disposed between the stitch holeand the retaining finger of the bobbin housing together with the part ofthe needle thread loop that leads to the sewing material. lf due todisplacement of the retaining finger toward the center of the bobbinhousing between the path of movement of the needle and the retainingfinger of the bobbin housing a passage space is provided for a threadcatcher, the thread catcher which moves below the plane of the bobbinhousing extending along a path of movement in a straight line orarcuately in a horizontal plane between the retaining finger of thebobbin housing and the path of movement of the needle may seize thelooper thread as well as the part of the needle thread loop goingto thematerial being sewn. In this manner assurance is given that on the onehand the thread catcher does not seize the part of the needle threadloop leading to the thread supply, and on the other hand the looperthread thus formed can during the normal sewing operation neither beseized by the point of the looper that seizes the needle thread, nor bythe horn controlling the loop dropping movement of the needle thread` lnorder to make the thread ends remaining on the sewing material short andthe ends remaining on the thread supply optimally long, it is necessaryto displace the cutting location of both threads from their location ofseizure at the thread catcher in the direction of the stitch hole. Anadvantageous solution of this problem is obtained in that the threadcatcher has a recess, known per se, extending in the direction of itspoint with a terminal edge forming the counter cutter for the cutter andabove the thread catcher a thread guide with a thread guiding surface isarranged which during the pull-out movement of the thread catcher movesabove its recess along a path of movement parallel to its path ofmovement oppositely to the thread catcher. If already one thread catcherwith a thread guide surface arranged in a fixed position would insurethat the threads to be cut that extend from their point of seizure onthe thread catcher obliquely upwardly come to rest in the recess, thenthe thread guide surface of the thread guide that moves opposite to thethread catcher affords in addition the security that the threads are notclamped between the thread catcher and the thread guide, and are notsqueezed off at a location that is not predetermined.

In order to obtain extremely short thread ends, the cutter is arrangedin accordance with a further development of the invention between`thread guide and the thread catcher and movable during the withdrawingmovement of the thread catcher upon a course of movement extendingparallel thereto. In this manner it is possible to sever the threadsclosely below the stitch hole so that the thread ends remaining on thesewing material are only of a length that corresponds essentially to thethickness of the stitch plate and to the vertical difference between thebottom side and the top side of the thread catcher.

An arrangement of thread catcher, thread guide and cutter which isstructurally simple and space saving, which simultaneously provides theopportunity of driving the parts moving oppositely to one another bymeans of a single rocking shaft, while interconnecting only two drawbarsis obtained, in that thread catcher, thread guide and cutter arearranged coaxially to one another and movable along paths of movementthat extend eccentrically to the looper.

In the arrangement in accordance with the invention of the aperture forthe looper thread provided in the looper housing, care must be taken inaddition besides the correct looper thread course that the bobbin withthe looper thread supply can be readily inserted into the upper part ofthe looper housing and can he inserted in the looper housing bottom partin as completely threaded condition as possible. This requirement is metin accordance with a further feature of the invention that the bobbinhousing bottom is provided laterally of the retaining finger with arecess that reaches up to its bearing rib and the looper housing top hasa bridge that extends into this recess on whose lower end the apertureforming the looper thread guide for the looper thread is formed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is described more indetail with reference to an embodiment illustrated in the drawings inwhich FIG. l is a front view ofa sewing machine,

FIG. 2 is a perspective illustration of the thread cutting arrangementand ofits drive mechanism,

FIG. 3 is a perspective exploded view of the individual parts ofthethread cutting device,

FIG. 4 is a perspective illustration ofa first embodiment ofa bobbinhousing,

FIG. 5 is a perspective illustration of a second embodiment ofa bobbinhousing,

FIG. 6 is a plan view of a part of the bottom of the housing inaccordance with FIG. 5,

FIG. 7 is a section through a looper with the bobbin housing inaccordance with FIG. 4,

FIG. 8 is a perspective illustration of the thread cutting deviceshortly before the threads are seized,

device during the withdrawing movement, and

DESCRIPTION OF THE INVENTION The standard 2 of the sewing machine ismounted on the base plate l (FIG. l) on which the horizontal arm 3 isformed that has head 4 at its end. In the arm 3 the armshaft S isjournalled which is in driving connection with the needle bar 7 thatcarries thread guiding needle 6 which moves up and down in the head 4.In the head of the sewing machine there is furthermore mounted thetake-up lever 8 for the thread that cooperates with the needle in aknown manner. Upon the armshaft 5 a belt wheel 9 is secured whichtransmits by way of a belt l0 and a wheel 11 the driving movements ofthe armshaft to the looper drive shaft 12 journalled in the base platel. The looper drive shaft 12 supports a pinion 13 which meshes with acooperating pinion 15 disposed upon a vertical looper shaft 14 and thusdrives the double stitch looper 16 which is mounted at the upper endofthe looper shaft I4 and rotates in a horizontal plane.

The double stitch looper 16 (FIG. 7) has a looper body I7 on which alooper point 18 is formed. ln the double stitch looper 16 a bobbinhousing 21 is journalled which is defined by a bobbin housing bottomportion 19 and a bobbin housing upper portion 20, and which has aretaining finger 22 at its surface that faces the needle 6, which fingerrests against an abutment 23 of the stitch plate 24 and secures thebobbin housing 2l against rotary movements. The lower part I9 of thebobbin housing has a bearing rib 25 which engages a guide groove 28formed by the looper body 17 and the cover segment 27 that carries thelooper horn 26. Furthermore, a side wall 29 is provided on the lowerpart 19 of the looper housing which supports at its upper end anabutment lug 30 for the housing member 31. The upper part 20 of thebobbin housing has a slot 33 along its side wall 32 (FIG. 4) thatextends obliquely upwardly and which ends below a tensioning spring 34for the looper thread in a bore 35 provided in the side wall 32. In theembodiment illustrated in FIG. 4 of the bobbin housing 21, the lsidewall 29 ofthe lower part 19 ofthe housing is provided with a recess 36between the stop finger 22 and the abutment 30 for the housing member 3linto which projects a downwardly extending bridge 37 that extendsclosely above the bearing rib 25 that is provided on the upper part 20of the bobbin housing. This bridge has an outlet opening 38 for thebobbin thread in the area of its lower end. The looper thread receivedby the bobbin 39 arranged in the bobbin housing 21 is guided from thebobbin through the obliquely upwardly extending slot 33, respectivelythe bore 35 of the upper part 20 of the bobbin housing, and from therebelow the tension spring 34 to a thread guide 40 provided onthe upperpart of the bobbin housing, and thence behind the side wall 29 of thelower part 19 ofthe bobbin housing to the looper thread outlet opening38 formed on the bridge 37 of the upper part of the bobbin housing andfrom there extends in the manner reflected by FIGS. 4 and 7 between theinner wall of the looper body 17 and the bobbin housing 21 through tothe stitch hole 41 in the stitch plate 24.

In the second embodiment of a looper housing illustrated in FIGS. 5 and6, it is likewise formed by the lower part 119 of the bobbin housing andan upper part ofthe bobbin housing and has a retaining finger 122 at itswall surface facing the needle 6 which rests against an abutment 23 ofthe stitch plate 24 and thus secures the bobbin housing 121 againstrotating. The lower part 119 of the bobbin housing 129 is likewiseprovided with a bearing rib 125 that engages a guiding groove 28 formedby the looper body 17 and the cover segment 27 that supports the looperhorn 26 which is fastened thereto. On the lower part 119 of the looperhousing a side wall 129 is also provided which at its upper end supportsan abutment lug for the housing member 31. The upper part 120 of thebobbin housing has a slot 133 along its side wall 132 that extendsobliquely upwardly, which terminates below a tension spring A, abutmentlug 130, which terminates in the area of the side wall 129 of the bobbinhousing between the` retaining finger 122 and the lug 130,and has at itsend an aperture 138 forming a guide for the looper thread formed in amanner reflected by FIG. 6. The looper thread in this embodiment of thebobbin housing extends l from the bobbin 139 disposed therein throughthe slot 133, respectively the bore 135, below the tension spring 134 tothe thread guide 140 arranged at its end,

vand thence alonglthe lower side of the rib 137 to the aperture 138defined at the end thereof and leading from there between the inner wallof the loope'rbody 17 and the bobbin housing 121 in a mannerillustrated'by FIG. 5, obliquely upwardly to the stitch hole 41 of thestitch plate 24.

At the bottom side of the base plate 1, a supporting plate 45 (FIG. 2)is secured which has two grooves 46, 47 that extend arcuately andconcentric relative to each other which are eccentric withrespectto thedouble stitch looper 16. The lower groove 46 that is disposed in ahorizontal plane serves as a guide path for a thread catcher 48 that isprovided therein, whose point 49 swings below the plane of the surfaceof the bobbin housing 21, 121 in a path of movement which extendsbetween the-'retaining finger 22,122 and the stitch hole 4l of thestitch plate 24. The thread catcher 48 (FIG. 3) has a recess forming acounter hook S0 at its lateral surface that faces the needlel 6 whichconnects with a groove 51 extending in the direction ofthe point 49 andwhich in turn ends in a bore 52. The terminal edge of the recess 51 orthe bore 52 defines a counter Vedge 53 for a cutter 54 that cooperateswith the thread catcher 48. At the end remote from its point a receivingbore 55 for a stud 56 is provided on the thread catcher 48 whichprojects through an arcuatelyextending slot 57 of the support plate 45arranged in the groove 46 and is received by a drawbar 58.

The cutter 54 (FIG. 3) arranged above the thread catcher 48 is likewiseof arcuate shape and is received in the upper groove 47 of the supportplate 45 which is wider with respect to the lower groove 46. For drivingthe cutter 54 which has an edge 59, it is provided with a bore60 whichis engaged by a stud 6l that projects through a slot 62 which islikewise arcuately shaped and is arranged laterally of the groove 46 inthe groove 471and is in its turn mounted on a drawbar 63.

Above the cutter 54 a thread guide 64 with a point 65 and a thread guidesurface 66 adjacent thereto is arranged in the groove 47 which receivesthe same. The arrangement of the thread guiding surface 66 is of suchnature that it moves during the relative opposite movements of threadcatcher 48 and thread guide 64 directly above the recess 51 in thethread catcher along a path that is parallel to their path of movement.The thread guide 64 has a bore 67 for its-operation which is engaged bythe stud'6l that projects into thebore 60 ofthe cutter 54.

As shown particularly in FIG. 2, a leaf spring 68 is provided upon theupper surface of the supporting plate 45 which rests upon the threadguide 64 and thereby holds the thread catcher 48, the catcher 54 andthethread guide 64 in the grooves 46, 47 coordinated therewith. At thelower side of the support plate 45 a further leaf spring 69 is securedwhich serves to clamp the looper thread at the end of the withdrawingmovement of the thread catcher 48 at the lower side of the support tplate 45.

For driving the thread catcher 48, respectively the cutter 54 and thethread guide 64, the two drawbars 58, respectively 63, which are engagedby the studs 56, 61 are linked to a crank 72 in a manner shown in FIGS.2 and 3 which is carried on rocking shaft 74 engaging a support member73 secured to the base plate 1. At its lower end the rocking shaft isprovided with a crank arm 75 whichis engaged by a drawbar 76. The freeend of the drawbar 76 is connected with a bifurcated member 77, which islinked to the drawbar of an electromagnet 78, which in turn is securedto the lower side of the base plate l by means of a support member 79.Between the support member 79 and a setting ring 80 provided on thebifurcated member 77, a spring 8l is arranged which is'tensioned duringthe thread seizing movement of the thread catcher 48, and then controlsthe thread withdrawing and cutting movement of the thread catcher. Itis, of course, also possible to carry out the movements of the threadcatcher 48, respectively the cutter 54 and the thread guide 64| with afour-joint trans-V mission that is in releasable connection with themain shaft of the sewing machine and which engages the crank arm 75 orthe drawbar 76.

The manner of operation of the thread cutting device is as follows:

At the end of the seam the sewing 'machine is briefly stopped with theneedle in a predetermined position, for example with the needle inlowermost position by means of a stopmatik-motor; in thisconnection tlhecircuit of the elec-- tromagnet 78 is closed` simultaneously. The magnetpulls up and locks the crank arm 75 in clockwise direction as seen inFIG. 2. As a result, the crank 72 is thereupon likewise swung inclockwise direction about the crankshaft 74 and transfers the rockingmovement by way of the drawbar 58 to the stud 56, to the thread catcher48. The thread catcher effects a counterclockwise movement as viewed inFIG. 8 and moves in this connection as seen in the direction ofsewingfrom its starting position behind the stitch-forming location inthe direction of the stitch hole 41. During` this movement of the threadcatcher 48, the needle 6 stitches again and the looper point 18 seizesthe loop of the needle' thread. During the guiding of the needle threadloop around the bobbin housing, the looper point 18 guides the part ofthe needle thread loop that leads to the needle thread supply over thetop of the bobbin housing 21, 121. Shortly before the greatest expansionof the needle thread loop, the point 49 of the.` thread catcher 48 hasreached the retaining finger 22, 122 of the bobbin housing 2l, 121 andmoves below the plane of the top surface of the bobbin housing betweenits retaining finger 22, 122 and the path of movement of the needle 6through into the needle thread loop. The part of the needle thread loopleading to the thread supply extends in this connection from `stitchhole 41 (FIG. 8) above the top side of the thread catcherI 48 over thetop side of the bobbin housing 21, 121 and thence to looper pointl8. Thepart ofthe needle thread loop that leads to the sewing material extendsfrom the looper point 18 at the bottom of the'bobbin housing 21, 121i.e. between the bobbin housing. and the bottom of the looper body 17through to the surface of the bobbin housing 21, 121 facing the needle6, and from there between the bobbin housing and the inner wall of thelooper body 17 through along the lower side of the thread catcher 48 tothe stitch hole 4l. The looper thread extends from its aperture 38, 138provided on its bobbin housing 2l, 121 likewise between the bobbinhousing 2l, 121 and the inner wall of the looper body 17 obliquelyupwardly along the lower side of the thread catcher 48 to the stitchhole 4l. The part of the needle thread loop and the looper threadleading to the material being sewn thus extend from the inner edge ofthe covering segment 27 below the point of the thread catcher 48 nearlyparallel to one another (FIGS. 7 and 8) to the stitch hole and duringthe further course of the movement of the thread catcher 48 rest againstthe side surface that faces tli needle, while they are simultaneouslypushed by this lateral` surface toward the stitch -holc 41 and are thustensioned. During the further course of the movement of the catcher, itpushes itself so far into the needle thread loop which drops due to thefurther turning of the looper 16 from the bobbin housing 2l, 121 untilthat part that leads to the sewing material comes to rest together withthe looper thread in the recess of the thread catcher 48 which forms acounter hook 50. The thread feeder 8 during this movement of the threadcatcher 48, with the needle thread tension open, pulls up the needlethread loop which is dropping down from the bobbin housing 21, 121respectively from vthe looper. The cutter, as well as also the threadguide 64, execute a rocking movement due to their connection with thedrawbar 63, respectively crank 72, which however is without influence onthe seizing of the thread as also on the course of the threads to beseized and cut.

ln the returning position of the thread catcher movement, theelectromagnet 78 is devoid of potential as a result of which the spring81 which is now released takes over the drive of the thread catcher 48,cutter 54 and thread guide 64. The thread catcher 48 moves back in thedirection of its initial position against its first direction ofmovement, and this connection as the needle thread tension is open pullsup needle thread, as well as looper thread with its counter hook 50.The'parts of needle and looper thread whichextend from the counter hook50 to the material being sewn now come into engagement with the threadguide surface 66 of the thread guide 64 that moves oppositely to thethread catcher 48 and during the withdrawing movement of the threadcatcher 48 are pressed from the recess 51 provided above the threadcatcher along a thread guide surface 66 which is parallel to its path ofmovement into the recess and thus is held away from the edge S9 of thecutter 54 which moves in opposite direction to the thread catcher 48,

i.e. in the direction to the stitch hole 41. Thus, during thewithdrawing movement of the thread catcher 48, the parts of needle andlooper thread leading to the material being sewn are pressed by thethread guide surface 66 of the thread guide 64 into the recess 51 of thethread catcher, while the parts of the needle and looper thread whichlead from the counter hook S of the thread `catcher 48 to the threadsupply extend -along the lower side of the thread, while the part of theneedle thread loop leading to the needle thread supply passes along thelower side of the thread catcher 48, and from there to the stitch hole4l, while the part of the looper thread leading from the counter hook 50to the looper thread supply is clamped in between the leaf spring andthe support plate 45 provided between the'lower side and the supportplate and leads from its clamping position below the plane of thesurface of the bobbin housing 21, 121 between its housing surface andthe inner wall of the looper body 17 through to the aperture 38, 138provided on the bobbin housing 2l, 121.

As soon as the thread take-up lever 8 has reached the upper region ofits dead point, the edge 53 provided on the thread catcher 48, as wellas also the cutter 54 which moves opposite to the thread catcher hasreached with its edge 59 the region of the stitch hole 41 and severs incooperation with the edge 53 of the thread catcher 48 the needle, aswell as the looper thread. Since the ends of needle and looper threadremaining on the material being sewn lead from the cutting location ofboth threads directly to the stitch hole 41 and from there to thematerial, they become optimally short, while the ends of needle andlooper thread remaining with the thread supply will be ofa lengthinsuring safe formation of the initial stitches of the next sewingcycle, due to the fact that they lead from the cutting location firstwithin the recess l provided at the top of the thread catcher 48 to thecounter hook 50 and from there along the lower side of the threadcatcher tothe stitch hole 41, or by way of the thread clamp 69 to thelooper exit opening 38,138.

Upon cuttig of both threads, the thread catcher 48 moves on in thedirectipn of its thread withdrawing movement and returns to its startingposition, while the thread guide 64, as well as also the cutter 54reverse their direction of movement due to their linkage with the stud61 of the drawbar 63, and now moving in the same direction as the threadcatcher 48 return likewise to their starting position.

Having now described our invention, what we desire to protect by letterspatent is set forth in the appended claims.

l. Thread cutting arrangement for double stitch sewing machines having alooper turning in a horizontal plane, a nee dle movable re ative to saidlooper, a bobbin housing Journalled in the looper, a stitch platedisposed above said looper having an abutment, said housing having aretaining finger for engaging said abutment to secure the same againstrotary movements and having an outlet opening for the looper threaddetermining the course of the looper thread between said stitch plateand said bobbin housing, a cutter below said stitch plate, a threadcatcher having a catcher point movable in a horizontal plane andcooperating with said cutter and having a recess for accommodating theneedle and looper threads adjacent said point, where the opening for thelooper thread is disposed below the plane of the surface of the bobbinhousing on the housing surface facing said needle, and adjacent theretaining finger, said point of said thread catcher being movable belowthe plane of the surface of the bobbin housing between the path ofmovement of the needle and of the retaining finger of the bobbinhousing.

2. Thread cutting device in accordance with claim l, where said threadcatcher has a groove on its upper surface extending in the direction ofsaid point, said groove terminating in an edge defining acounter cutterfor said cutter, a'thread guide having a thread guiding surface disposedabove said thread catcher movable above said groovealong a path ofmovement parallel to the path of movement thereof opposite to the pathof movement of said thread catcher.

3. Thread cutting device in accordance with claim 2 where said cutter isdisposed between said thread guide and said thread catcher and movablein opposite direction during the pull-out movement of said threadcatcher along a path of movement extending parallel to the path ofmovement of said thread catcher.

4. Thread cutting device in accordance with claim 3, where said threadcatcher, said thread guide and said cutter are arranged coaxiallyrelative to one another and along paths of movement extendingeccentrically to said looper.

5. Thread cutting device in accordance with claim l, where' I UNITEDSTATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 5,658,021Dated Alm 25,1972

Inventods) Kristen Hedegaard, Anton Leesmeieter` It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below: `Amend tne title of the aplceton es follows: lllllllGEnEl=ifl` EUR CUTTINE ebeteet, line l: page2, line 45| pee lines and 27; and Page 9, lines 14 and l5 Change dou le'to --leek;

Page 2, line 5 delete "OT eeteher"';

Page 5, line l5 Chengje *"etovp" to retaining-q Page 5 line jda.,lete"neusing'Ventend insert instead "member finger-e;-

llagge 9, line 2e, and Page lO, line Zend lines O/l, Change "nousinte`member" to boletin membefflnger;

l) e l5, line l9 delete "tneed vfeede" and nert instead y talee-uplever-- t Signed and sealed thisv 15th day of August 1972.

THREADS ON LOCK Sl TCH SEWING MEMBRES-- (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestng Officer CommissionerIof Patents USCOMM'DC 50376-P69 U.S. GOVERNMENT PRINTING OFFICE |959 0365-334

1. Thread cutting arrangement for double stitch sewing machines having alooper turning in a horizontal plane, a needle movable relative to saidlooper, a bobbin housing journalled in the looper, a stitch platedisposed above said looper having an abutment, said housing having aretaining finger for engaging said abutment to secure the same againstrotary movements and having an outlet opening for the looper threaddetermining the course of the looper thread between said stitch plateand said bobbin housing, a cutter below said stitch plate, a threadcatcher having a catcher point movable in a horizontal plane andcooperating with said cutter and having a recess for accommodating theneedle and looper threads adjacent said point, where the opening for thelooper thread is disposed below the plane of the surface of the bobbinhousing on the housing surface facing said needle, and adjacent theretaining finger, said point of said thread catcher being movable belowthe plane of the surface of the bobbin housing between the path ofmovement of the needle and of the retaining finger of the bobbinhousing.
 2. Thread cutting device in accordance with claim 1, where saidthread catcher has a groove on its upper surface extending in thedirection of said point, said groove terminating in an edge definingacounter cutter for said cutter, a thread guide having a thread guidingsurface disposed above said thread catcher movable above said groovealong a path of movement parallel to the path of movement thereofopposite to the path of movement of said thread catcher.
 3. Threadcutting device in accordance with claim 2 where said cutter is disposedbetween said thread guide and said thread catcher and movable inopposite direction during the pull-out movement of said thread catcheralong a path of movement extending parallel to the path of movement ofsaid thread catcher.
 4. Thread cutting device in accordance with claim3, where said thread catcher, said thread guide and said cutter arearranged coaxially relative to one another and along paths of movementextending eccentrically to said looper.
 5. Thread cutting device inaccordance with claim 1, where the lower part of said bobbin housing isprovided with a bearing rib laterally of said retaining finger, a recessto which said finger extends, and the upper part of said bobbin housinghas a bridge extending into said recess at the lower end of which saidopening for the looper thread is provided.